Water dispersible substituted polydioxythiophenes made with fluorinated polymeric sulfonic acid colloids

ABSTRACT

Compositions are provided comprising aqueous dispersions of polythiophenes having homopolymers or co-polymers of Formula I(a) or Formula I(b) and at least one colloid-forming polymeric acid. Methods of making such compositions and using them in organic electronic devices are further provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.10/669,494, filed Sep. 24, 2003, and claims priority from U.S.Provisional Application No. 60/464,370, filed Apr. 22, 2003.

FIELD OF THE INVENTION

The invention relates to aqueous dispersions of electrically conductingpolymers of thiophene, wherein the electrically conducting polymer issynthesized in the presence of polymeric acid colloids.

BACKGROUND OF THE INVENTION

Electrically conducting polymers have been used in a variety of organicelectronic devices, including in the development of electroluminescent(“EL”) devices for use in light emissive displays. With respect to ELdevices, such as organic light emitting diodes (OLEDs) containingconducting polymers, such devices generally have the followingconfiguration:

-   -   anode/buffer layer/EL material/cathode        The anode is typically any material that is transparent and has        the ability to inject holes into the EL material, such as, for        example, indium/tin oxide (ITO). The anode is optionally        supported on a glass or plastic substrate. EL materials include        fluorescent dyes, fluorescent and phosphorescent metal        complexes, conjugated polymers, and mixtures thereof. The        cathode is typically any material (such as, e.g., Ca or Ba) that        has the ability to inject electrons into the EL material.

The buffer layer is typically an electrically conducting polymer andfacilitates the injection of holes from the anode into the EL materiallayer. The buffer layer can also be called a hole-injection layer, ahole transport layer, or may be characterized as part of a bilayeranode. Typical conducting polymers employed as buffer layers includepolyaniline and polydioxythiophenes such aspoly(3,4-ethylenedioxythiophene) (PEDT). These materials can be preparedby polymerizing aniline or dioxythiophene monomers in aqueous solutionin the presence of a water soluble polymeric acid, such aspoly(styrenesulfonic acid) (PSS), as described in, for example, U.S.Pat. No. 5,300,575 entitled “Polythiophene dispersions, their productionand their use.” A well known PEDT/PSS material is Baytron®-P,commercially available from H. C. Starck, GmbH (Leverkusen, Germany).

The aqueous electrically conductive polymer dispersions synthesized withwater soluble polymeric sulfonic acids have undesirable low pH levels.The low pH can contribute to decreased stress life of an EL devicecontaining such a buffer layer, and contribute to corrosion within thedevice. Accordingly, there is a need for compositions and layersprepared there from having improved properties.

Electrically conducting polymers which have the ability to carry a highcurrent when subjected to a low electrical voltage, also have utility aselectrodes for electronic devices, such as thin film field effecttransistors. In such transistors, an organic semiconducting film whichhas high mobility for electron and/or hole charge carriers, is presentbetween source and drain electrodes. A gate electrode is on the oppositeside of the emiconducting polymer layer. To be useful for the electrodeapplication, the electrically conducting polymers and the liquids fordispersing or dissolving the electrically conducting polymers have to becompatible with the semiconducting polymers and the solvents for thesemiconducting polymers to avoid re-dissolution of either conductingpolymers or semiconducting polymers. The electrical conductivity of theelectrodes fabricated from the electrically conducting polymers shouldbe greater than 10 S/cm (where S is a reciprocal ohm). However, theelectrically conducting polythiophenes made with a polymeric acidtypically provide conductivity in the range of ˜10⁻³ S/cm or lower. Inorder to enhance conductivity, conductive additives may be added to thepolymer. However, the presence of such additives can deleteriouslyaffect the processability of the electrically conducting polythiophene.Accordingly, there is a need for improved conductive polythiophenes.

SUMMARY OF THE INVENTION

New compositions are provided comprising aqueous dispersions of at leastone polythiophene and at least one colloid-forming polymeric acid,wherein the polythiophene comprises the Formula I(a) or I(b):

wherein

-   -   with respect to Formula I(a):

-   -   R″ is the same or different at each occurrence and is selected        from hydrogen, alkyl, heteroalkyl, alkenyl, heteroalkenyl,        alcohol, amidosulfonate, benzyl, carboxylate, ether, ether        carboxylate, ether sulfonate, and urethane, with the proviso        that at least one R″ is not hydrogen.    -   m is 2 or 3, and    -   n is at least about 4;    -   and, with respect to Formula I(b):

-   -   R′₁ and R₁ are independently selected from hydrogen or alkyl, or    -   R′₁ and R₁ taken together form an alkylene chain having 1 to 4        carbon atoms, which may optionally be substituted by alkyl or        aromatic groups having 1 to 12 carbon atoms, or a        1,2-cyclohexylene radical, and    -   n is at least about 4.

In another embodiment, there are provided methods for synthesizingaqueous dispersions of at least one polythiophene comprising at leastone of the Formula I(a) or Formula I(b) and at least one colloid-formingpolymeric acid. One method of producing an aqueous dispersion of thepolythiophene and at least one colloid-forming polymeric acid,comprises:

-   -   (a) providing a homogeneous aqueous mixture of water and at        least one thiophene monomer, said thiophene having Formula II(a)        or II(b):

-   -   wherein R″, R′₁, and R₁ and m are as defined above;    -   (b) providing an aqueous dispersion of the colloid-forming        polymeric acid;    -   (c) combining the thiophene mixture with the aqueous dispersion        of the colloid-forming polymeric acid, and    -   (d) combining an oxidizing agent and a catalyst, in any order,        with the aqueous dispersion of the colloid-forming polymeric        acid before or after the combining of step (c).

In another embodiment, new compositions are provided comprising at leastone polythiophene, at least one colloid-forming polymeric acid, and atleast one co-dispersing liquid, wherein the polythiophene comprises theFormula I(a) or I(b), as described above.

In another embodiment, electronic devices comprising at least one layercomprising the new composition are provided.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE FIGURES

The invention is illustrated by way of example and not limited in theaccompanying figures.

FIG. 1 illustrates a cross-sectional view of an electronic device thatcomprises a buffer layer comprising one embodiment of the newcomposition.

FIG. 2 illustrates a cross-sectional view of a thin film field effecttransistor that comprises an electrode comprising the new composition.

FIG. 3 illustrates the change in conductivity of polythiophene/FSAaqueous colloidal dispersion® films with the ratio of oxidizing agent tomonomer in the polymerization reaction.

FIG. 4 illustrates the change in conductivity of polythiophene/FSAaqueous colloidal dispersion films with the ratio of FSA to monomer inthe polymerization reaction.

FIG. 5 illustrates the operation lifetime of OLED devices with greenlight-emitting polymers.

FIG. 6 illustrates the operation lifetime of OLED devices with redlight-emitting polymers.

FIG. 7 illustrates the operation lifetime of OLED devices with bluelight-emitting polymers.

FIG. 8( a) through FIG. 8( d) illustrate the effect of the pH of thePEDT/PSSA buffer layer on OLED device performance.

FIG. 9( a) through FIG. 9( c) illustrate the effect of the pH of thepolythiophene/FSA aqueous colloidal dispersion buffer layer on OLEDdevice performance.

FIG. 10 illustrates the change in ITO thickness when immersed indispersions of polythiophene/FSA aqueous colloidal dispersion orPEDT/PSSA.

FIG. 11 illustrates a device luminance and voltage as a function oftime.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, compositions are provided comprising aqueousdispersions of at least one polythiophenes having Formula I(a) orFormula I(b), and at least one colloid-forming polymeric acid.

The new aqueous dispersion of at least one polythiophene and at leastone colloid-forming polymeric acid comprising at least one polythiophenehaving Formula I(a) or Formula I(b) can be prepared when at least onethiophene monomer having Formula II(a) or II(b) are polymerizedchemically in the presence of colloid-forming polymeric acids.

Further, it has been discovered that use of a polymeric acid that is notwater soluble in preparation of an aqueous dispersion of thepolythiophenes having Formula II(a) or Formula II(b) yields acomposition with superior electrical properties. In one embodiment, theaqueous dispersions of the new composition comprises electricallyconductive minute particles that are stable in the aqueous mediumwithout forming a separate phase over a long period of time before ause. In one embodiment, layers comprising the new composition do notre-disperse once dried into films or layers during fabrication of theelectronic device.

Compositions according to one embodiment of the new composition comprisea continuous aqueous phase in which at least one polythiophene and atleast one colloid-forming polymeric acid are dispersed.

Polythiophenes contemplated for use in the new composition are made fromat least one monomer having the following Formulae II(a) or II(b) tocreate either homopolymers or co-polymers, wherein:

-   -   R″ is the same or different at each occurrence and is selected        from hydrogen, alkyl, heteroalkyl, alkenyl, heteroalkenyl,        alcohol, amidosulfonate, benzyl, carboxylate, ether, ether        carboxylate, ether sulfonate, sulfonate, and urethane, with the        proviso that at least one R″ is not hydrogen;    -   R′₁ and R₁ are independently selected from hydrogen or alkyl, or        R₁ and R₁′ taken together form an alkylene chain having 1 to 4        carbon atoms, which may optionally be substituted by alkyl or        aromatic groups having 1 to 12 carbon atoms, or a        1,2-cyclohexylene radical.

Thiophenes of the new composition have the same general structure asprovided above, wherein R₁ and R₁′ are substituted for the “OR₁” and“OR₁′” substituents.

The polythiophenes of the new composition can be homopolymers, or theycan be copolymers of two or more thiophene monomers. The aqueousdispersions of polythiophene and colloid-forming polymeric acid cancomprise one or more than one polythiophene polymer and one or more thanone colloid-forming polymeric acid.

As used herein, the term “dispersion” refers to a continuous liquidmedium containing a suspension of minute particles. The “continuousmedium” comprises an aqueous liquid. As used herein, the term “aqueous”refers to a liquid that has a significant portion of water and in oneembodiment it is at least about 40% by weight water. As used herein, theterm “colloid” refers to the minute particles suspended in thecontinuous medium, said particles having a nanometer-scale particlesize. As used herein, the term “colloid-forming” refers to substancesthat form minute particles when dispersed in aqueous solution, i.e.,“colloid-forming” polymeric acids are not water-soluble.

As used herein, the term “co-dispersing liquid” refers to a substancewhich is liquid at room temperature and is miscible with water. As usedherein, the term “miscible” means that the co-dispersing liquid iscapable of being mixed with water (at concentrations set forth hereinfor each particular co-dispersing liquid) to form a substantiallyhomogeneous solution.

The term “layer” or “film” refers to a coating covering a desired area.The area can be as large as an entire device or as small as a specificfunctional area such as the actual visual display, or as small as asingle sub-pixel. Films can be formed by any conventional depositiontechnique, including vapor deposition and liquid deposition. Typicalliquid deposition techniques include, but are not limited to, continuousdeposition techniques such as spin coating, gravure coating, curtaincoating, dip coating, slot-die coating, spray coating, and continuousnozzle coating; and discontinuous deposition techniques such as ink jetprinting, gravure printing, and screen printing.

As used herein, the term “alkyl” refers to a group derived from analiphatic hydrocarbon and includes linear, branched and cyclic groupswhich may be unsubstituted or substituted. The term “heteroalkyl” isintended to mean an alkyl group, wherein one or more of the carbon atomswithin the alkyl group has been replaced by another atom, such asnitrogen, oxygen, sulfur, and the like. The term “alkylene” refers to analkyl group having two points of attachment.

As used herein, the term “alkenyl” refers to a group derived from analiphatic hydrocarbon having at least one carbon-carbon double bond, andincludes linear, branched and cyclic groups which may be unsubstitutedor substituted. The term “heteroalkenyl” is intended to mean an alkenylgroup, wherein one or more of the carbon atoms within the alkenyl grouphas been replaced by another atom, such as nitrogen, oxygen, sulfur, andthe like. The term “alkenylene” refers to an alkenyl group having twopoints of attachment.

As used herein, the following terms for substituent groups refer to theformulae given below:“alcohol” —R³—OHamidosulfonate —R³—C(O)N(R⁶)R⁴—SO₃Z“benzyl” —CH₂—C₆H₅“carboxylate” —R³—C(O)O—Z“ether” —R³—O—R⁵“ether carboxylate” —R³—O—R⁴—C(O)O—Z“ether sulfonate” —R³—O—R⁴—SO₃Z“sulfonate” —R³—SO₃Z“urethane” —R³—O—C(O)—N(R⁶)₂

-   -   where all “R” groups are the same or different at each        occurrence and:        -   R³ is a single bond or an alkylene group        -   R⁴ is an alkylene group        -   R⁵ is an alkyl group        -   R⁶ is hydrogen or an alkyl group        -   Z is H, alkali metal, alkaline earth metal, N(R⁵)₄ or R⁵.

Any of the above groups may further be unsubstituted or substituted, andany group may have F substituted for one or more hydrogens, includingperfluorinated groups.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Also, use of the “a” or “an” are employed to describe elements andcomponents of the invention. This is done merely for convenience and togive a general sense of the invention. This description should be readto include one or at least one and the singular also includes the pluralunless it is obvious that it is meant otherwise.

In one embodiment, the polythiophene has Formula I(a) where m is two,one R″ is an alkyl group of more than 5 carbon atoms, and all other R″are hydrogen.

In one embodiment of Formula I(a), at least one R″ group has at leastone fluorine substituent.

In one embodiment of Formula I(a), the R″ substituents on the fusedalicyclic ring on the thiophene should offer improved solubility of themonomers in water and facilitate polymerization in the presence of thepolymeric acid colloids. In another embodiment, the resultingpolythiophene/colloidal polymeric acid composition has reduced particlesize and dispersion stability.

In one embodiment, the polythiophene is a poly[(sulfonicacid-propylene-ether-methylene-3,4-dioxyethylene)thiophene]. In oneembodiment, the polythiophene is apoly[(propyl-ether-ethylene-3,4-dioxyethylene)thiophene].

In one embodiment, the polythiophene has Formula I(b) where R₁ and R₁′taken together form an alkylene chain having 1 to 4 carbon atoms. Inanother embodiment, the polydioxythiophene ispoly(3,4-ethylenedioxythiophene).

Colloid-forming polymeric acids contemplated for use in the newcompositions are insoluble in water, and form colloids when dispersedinto an aqueous medium. The polymeric acids typically have a molecularweight in the range of about 10,000 to about 4,000,000.

In one embodiment, the polymeric acids have a molecular weight of about100,000 to about 2,000,000. Polymeric acid colloid particle sizetypically ranges from 2 nanometers (nm) to about 140 nm. In oneembodiment, the colloids have a particle size of 2 nm to about 30 nm.

Any polymeric acid that is colloid-forming when dispersed in water issuitable for use to make the new compositions. In one embodiment, thecolloid-forming polymeric acid comprises at least one polymeric acidselected form polymer sulfonic acid, polymeric phosphoric acids,polymeric phosphonic acids, polymeric carboxylic acids, and polymericacrylic acids, and mixtures thereof. In another embodiment, thepolymeric sulfonic acid is fluorinated. In still another embodiment, thecolloid-forming polymeric sulfonic acid is perfluorinated. In yetanother embodiment, the colloid-forming polymeric sulfonic acidcomprises a perfluoroalkylenesulfonic acid.

In still another embodiment, the colloid-forming polymeric acidcomprises a highly-fluorinated sulfonic acid polymer (“FSA polymer”).“Highly fluorinated” means that at least about 50% of the total numberof halogen and hydrogen atoms in the polymer are fluorine atoms, an inone embodiment at least about 75%, and in another embodiment at leastabout 90%. In one embodiment, the polymer is perfluorinated. The term“sulfonate functional group” refers to either to sulfonic acid groups orsalts of sulfonic acid groups, and in one embodiment alkali metal orammonium salts. The functional group is represented by the formula —SO₃Xwhere X is a cation, also known as a “counterion”. X may be H, Li, Na, Kor N(R₁)(R₂)(R₃)(R₄), and R₁, R₂, R₃, and R₄ are the same or differentand are and in one embodiment H, CH₃ or C₂H₅. In another embodiment, Xis H, in which case the polymer is said to be in the “acid form”. X mayalso be multivalent, as represented by such ions as Ca⁺⁺, and Al⁺⁺⁺. Itis clear to the skilled artisan that in the case of multivalentcounterions, represented generally as M^(n+), the number of sulfonatefunctional groups per counterion will be equal to the valence “n”.

In one embodiment, the FSA polymer comprises a polymer backbone withrecurring side chains attached to the backbone, the side chains carryingcation exchange groups. Polymers include homopolymers or copolymers oftwo or more monomers. Copolymers are typically formed from anonfunctional monomer and a second monomer carrying the cation exchangegroup or its precursor, e.g., a sulfonyl fluoride group (—SO₂F), whichcan be subsequently hydrolyzed to a sulfonate functional group. Forexample, copolymers of a first fluorinated vinyl monomer together with asecond fluorinated vinyl monomer having a sulfonyl fluoride group(—SO₂F) can be used. Possible first monomers include tetrafluoroethylene(TFE), hexafluoropropylene, vinyl fluoride, vinylidine fluoride,trifluoroethylene, chlorotrifluoroethylene, perfluoro(alkyl vinylether), and combinations thereof. TFE is a preferred first monomer.

In other embodiments, one other monomer includes fluorinated vinylethers with sulfonate functional groups or precursor groups which canprovide the desired side chain in the polymer. Additional monomers,including ethylene, propylene, and R—CH═CH₂ where R is a perfluorinatedalkyl group of 1 to 10 carbon atoms, can be incorporated into thesepolymers if desired. The polymers may be of the type referred to hereinas random copolymers, that is copolymers made by polymerization in whichthe relative concentrations of the co-monomers are kept as constant aspossible, so that the distribution of the monomer units along thepolymer chain is in accordance with their relative concentrations andrelative reactivities. Less random copolymers, made by varying relativeconcentrations of monomers in the course of the polymerization, may alsobe used. Polymers of the type called block copolymers, such as thatdisclosed in European Patent Application No. 1 026 152 A1, may also beused.

In one embodiment, FSA polymers for use in the new composition include ahighly fluorinated, and in one embodiment perfluorinated, carbonbackbone and side chains represented by the formula—(O—CF₂CFR_(f))_(a)—O—CF₂CFR′_(f)SO₃Xwherein Rf and R′f are independently selected from F, Cl or aperfluorinated alkyl group having 1 to 10 carbon atoms, a=0, 1 or 2, andX is H, Li, Na, K or N(R1)(R2)(R3)(R4) and R1, R2, R3, and R4 are thesame or different and are and in one embodiment H, CH₃ or C₂H₅. Inanother embodiment X is H. As stated above, X may also be multivalent.

In one embodiment, the FSA polymers include, for example, polymersdisclosed in U.S. Pat. No. 3,282,875 and in U.S. Pat. Nos. 4,358,545 and4,940,525. An example of preferred FSA polymer comprises aperfluorocarbon backbone and the side chain represented by the formula—O—CF₂CF(CF₃)—O—CF₂CF₂SO₃Xwhere X is as defined above. FSA polymers of this type are disclosed inU.S. Pat. No. 3,282,875 and can be made by copolymerization oftetrafluoroethylene (TFE) and the perfluorinated vinyl etherCF₂═CF—O—CF₂CF(CF₃)—O—CF₂CF₂SO₂F,perfluoro(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride) (PDMOF),followed by conversion to sulfonate groups by hydrolysis of the sulfonylfluoride groups and ion exchanged as necessary to convert them to thedesired ionic form. An example of a polymer of the type disclosed inU.S. Pat. Nos. 4,358,545 and 4,940,525 has the side chain —O—CF₂CF₂SO₃X,wherein X is as defined above. This polymer can be made bycopolymerization of tetrafluoroethylene (TFE) and the perfluorinatedvinyl ether CF₂═CF—O—CF₂CF₂SO₂F, perfluoro(3-oxa-4-pentenesulfonylfluoride) (POPF), followed by hydrolysis and further ion exchange asnecessary.

In one embodiment, the FSA polymers for use in the new compositiontypically have an ion exchange ratio of less than about 33. In thisapplication, “ion exchange ratio” or “IXR” is defined as number ofcarbon atoms in the polymer backbone in relation to the cation exchangegroups. Within the range of less than about 33, IXR can be varied asdesired for the particular application. In one embodiment, the IXR isabout 3 to about 33, and in another embodiment about 8 to about 23.

The cation exchange capacity of a polymer is often expressed in terms ofequivalent weight (EW). For the purposes of this application, equivalentweight (EW) is defined to be the weight of the polymer in acid formrequired to neutralize one equivalent of sodium hydroxide. In the caseof a sulfonate polymer where the polymer has a perfluorocarbon backboneand the side chain is —O—CF₂—CF(CF₃)—O—CF₂—CF₂—SO₃H (or a salt thereof),the equivalent weight range which corresponds to an IXR of about 8 toabout 23 is about 750 EW to about 1500 EW. IXR for this polymer can berelated to equivalent weight using the formula: 50 IXR+344=EW. While thesame IXR range is used for sulfonate polymers disclosed in U.S. Pat.Nos. 4,358,545 and 4,940,525, e.g., the polymer having the side chain—O—CF₂CF₂SO₃H (or a salt thereof), the equivalent weight is somewhatlower because of the lower molecular weight of the monomer unitcontaining a cation exchange group. For the preferred IXR range of about8 to about 23, the corresponding equivalent weight range is about 575 EWto about 1325 EW. IXR for this polymer can be related to equivalentweight using the formula: 50 IXR+178=EW.

The synthesis of FSA polymers is well known. The FSA polymers can beprepared as colloidal aqueous dispersions. They may also be in the formof dispersions in other media, examples of which include, but are notlimited to, alcohol, water-soluble ethers, such as tetrahydrofuran,mixtures of water-soluble ethers, and combinations thereof. In makingthe dispersions, the polymer can be used in acid form. U.S. Pat. Nos.4,433,082, 6,150,426 and WO 03/006537 disclose methods for making ofaqueous dispersions. After the dispersion is made, the concentration andthe dispersing liquid composition can be adjusted by methods known inthe art.

In one embodiment, aqueous dispersions of the colloid-forming polymericacids, including FSA polymers, have particle sizes as small as possibleand an EW as small as possible, so long as a stable colloid is formed.

Aqueous dispersions of FSA polymer are available commercially as Nafion®dispersions, from E. I. du Pont de Nemours and Company (Wilmington,Del.).

In one embodiment, the thiophene monomers having Formula II(a) orFormula II(b) are oxidatively polymerized in water comprising at leastone polymeric acid colloids. Typically, the thiophene monomers arecombined with or added to an aqueous dispersion containing apolymerization catalyst, an oxidizing agent, and colloidal polymericacid particles dispersed therein. In this embodiment, the order ofcombination or addition may vary provided that when the oxidizing agentand catalyst is combined with the monomers at least a portion of thecolloid-forming polymeric acid is present. In one embodiment, thereaction mixture may further comprise a co-dispersing agent, a co-acid,or mixtures thereof.

In one embodiment, the colloid-forming polymeric acid is an FSA, andco-dispersing liquid of the aqueous FSA dispersion is optionally removedprior to or after polymerization of thiophene monomers.

In one embodiment, the thiophene monomers are combined with the aqueousreaction mixture comprising colloid-forming polymeric acid particles,the oxidizing agent and the catalyst by dispensing the thiophene monomerin a controlled rate of addition while continuously mixing the reactionmixture to form a monomer-meniscus in the reaction mixture.

In one embodiment, the oxidizing agent predissolved in water is combinedwith the aqueous reaction mixture comprising colloid-forming polymericacid particles, thiophene monomer and the catalyst therein by dispensingthe oxidizing agent solution in a controlled rate of addition whilecontinuously mixing the reaction mixture.

In one embodiment, the oxidizing agent and the thiophene monomer areadded separately and simultaneously to the reaction mixture, at the sameor different controlled rates of addition, to achieve the final desiredquantity of oxidizing agent, so as to consume the monomer at acontrolled rate in the oxidative polymerization reaction.

In one embodiment, the controlled rate of addition of thiophene monomeris determined in view of the quantity of materials used, with the goalof controlling the rate of monomer addition from the dispensingmechanism to ensure dissolution in the reaction mixture quickly. Withthe controlled addition, the polymerization and oxidation chemistry takeplace in an even and uniform manner. Examples of the dispensingmechanism include, but are not limited to, use of tubing, syringes,pipettes, nozzle guns, sprayers, hoses, pipes and the like. In oneembodiment, a perforated end, such as a fritted-glass plate, or smalldiameter tubing attached to the equipment described above is used forcreating a monomer-meniscus in the reaction mixture.

The rate of addition depends upon the size of the reaction, the speed atwhich the solution is stirred and the geometry and number of thedispensing ends of the dispensing mechanism orifice. In one embodiment,the dispensing end of the dispensing mechanism is submerged in thereaction mixture containing the aqueous colloid-forming polymeric acid.For example, addition rates of thiophene monomer of about 1-1000 microliter per hour for a reaction mixture size of about 100-500 grams ofaqueous colloid-forming polymeric acid composition can be used. In oneembodiment the rate of addition is between about 5 and 100 micro litersper hour for about 500 grams of the aqueous colloid-forming polymericacid. For reaction mixtures of other sizes (larger or smaller), the rateof addition can be linearly scaled in the appropriate direction.

In one embodiment, at least one co-dispersing liquid is added to thereaction mixture prior to termination of the polymerization of thethiophene monomers. In another embodiment, at least one co-dispersingliquid is added to the reaction mixture after the termination of thepolymerization of the thiophene. In another embodiment, a portion of atleast one co-dispersing liquid is added prior to termination of thethiophene polymerization and an additional quantity of at least oneco-dispersing liquid is added after termination of the polymerization ofthe thiophene.

Polymerization catalysts include, but are not limited to, ferricsulfate, ferric chloride, other materials having a higher oxidationpotential than the oxidizing agent, and mixtures thereof.

Oxidizing agents include, but are not limited to, sodium persulfate,potassium persulfate, ammonium persulfate, and the like, includingcombinations thereof. In one embodiment, the oxidative polymerizationresults in a stable, aqueous dispersion containing positively chargedconductive polymeric thiophene that is charge balanced by the negativelycharged side chains of the polymeric acids contained within thecolloids, for example, sulfonate anion, carboxylate anion, acetylateanion, phosphorate anion, phosphonate anion, combinations, and the like.

In one embodiment, the method of making the new composition comprisingat least one polythiophene having Formula I(a) or Formula I(b) and atleast one colloid-forming polymer acid includes: (a) providing anaqueous dispersion of a polymer acid; (b) adding an oxidizing agent tothe dispersion of step (a); (c) adding a catalyst to the dispersion ofstep (b); and (d) adding a thiophene monomer to the dispersion of step(c). One alternative embodiment to the above described method includesadding the thiophene monomer to the aqueous dispersion of a polymericacid prior to adding the oxidizing agent. Another embodiment is tocreate a homogenous aqueous mixture of water and the thiophene havingFormula II(a) or Formula II(b), with concentrations which typically arein the range of about 0.5% by weight to about 2.0% by weight thiophene,and add this thiophene mixture to the aqueous dispersion of thepolymeric acid before adding the oxidizing agent and catalyst.

The polymerization can be carried out in the presence of co-dispersingliquids which are miscible with water. Examples of suitableco-dispersing liquids include, but are not limited to ethers, alcohols,alcohol ethers, cyclic ethers, ketones, nitriles, sulfoxides, andcombinations thereof. In one embodiment, the amount of co-dispersingliquid should be less than about 30% by volume. In one embodiment, theamount of co-dispersing liquid is less than about 60% by volume. In oneembodiment, the amount of co-dispersing liquid is between about 5% to50% by volume. In one embodiment, the co-dispersing liquid comprises analcohol. In one embodiment, the co-dispersing liquid comprises at leastone from n-propanol, isopropanol, t-butanol, methanol dimethylacetamide,dimethylformamide, N-methylpyrrolidone.

The polymerization can be carried out in the presence of a co-acid. Theacid can be an inorganic acid, such as HCl, sulfuric acid, and the like,or an organic acid, such as p-toluenesulfonic acid,dodecylbenzenesulfonic acid, methanesulfonic acid,trifluoromethanesulfonic acid, camphorsulfonic acid, acetic acid and thelike. Alternatively, the co-acid can be a water soluble polymeric acidsuch as poly(styrenesulfonic acid),poly(2-acrylamido-2-methyl-1-propanesulfonic acid, or the like, or asecond colloid-forming acid, as described above. Combinations ofco-acids can be used.

The co-acid can be added to the reaction mixture at any point in theprocess prior to the addition of either the oxidizing agent or thethiophene monomer, whichever is added last. In one embodiment, theco-acid is added before both the thiophene monomer and thecolloid-forming polymeric acid, and the oxidizing agent is added last.In one embodiment the co-acid is added prior to the addition of thethiophene monomer, followed by the addition of the colloid-formingpolymeric acid, and the oxidizing agent is added last.

The co-dispersing liquid can be added to the reaction mixture at anypoint before, during or after the thiophene polymerization.

In one embodiment, compositions are provided comprising aqueousdispersions of polydioxythiophenes, colloid-forming polymeric acids, andat least one co-dispersing liquid. The addition of at least oneco-dispersing liquid to aqueous dispersions of poly(dioxythiophenes) andcolloid-forming polymeric acids after polymerization can result inpolymer dispersions having better wettability, and processability,processable viscosity, a substantially reduced number of largeparticles, improved stability of the dispersion, improvedink-jetability, enhanced conductivity, or combinations thereof.Surprisingly, it has been discovered that OLED devices having bufferlayers made from such dispersions also have higher efficiencies andlonger lifetimes.

Co-dispersing liquids contemplated for use in the new composition aregenerally polar, water-miscible organic liquids. Examples of suitabletypes of co-dispersing liquids include, but are not limited to, ethers,cyclic ethers, alcohols, alcohol ethers, ketones, nitriles, sulfides,sulfoxides, amides, amines, carboxylic acids, and the like, as well ascombinations of any two or more thereof.

Exemplary ether co-dispersing liquids contemplated for use in the newcomposition include, but are not limited to, diethyl ether, ethyl propylether, dipropyl ether, diisopropyl ether, dibutyl ether, methyl t-butylether, glyme, diglyme, benzyl methyl ether, isochroman, 2-phenylethylmethyl ether, n-butyl ethyl ether, 1,2-diethoxyethane, sec-butyl ether,diisobutyl ether, ethyl n-propyl ether, ethyl isopropyl ether, n-hexylmethyl ether, n-butyl methyl ether, methyl n-propyl ether, and the like,as well as combinations of any two or more thereof.

Exemplary cyclic ether co-dispersing liquids contemplated for use in thenew composition include, but are not limited to, 1,4-dioxane,tetrahydrofuran, tetrahydropyran, 4 methyl-1,3-dioxane,4-phenyl-1,3-dioxane, 1,3-dioxolane, 2-methyl-1,3-dioxolane,1,3-dioxane, 2,5-dimethoxytetrahydrofuran,2,5-dimethoxy-2,5-dihydrofuran, and the like, as well as combinations ofany two or more thereof. In one embodiment, the cyclic etherco-dispersing liquid is tetrahydrofuran, tetrahydropyran, or1,4-dioxane.

Exemplary alcohol co-dispersing liquids contemplated for use in the newcomposition include, but are not limited to, methanol, ethanol,1-propanol, 2-propanol (i.e., isopropanol), 1-butanol, 2-butanol,2-methyl-1-propanol (i.e., isobutanol), 2-methyl-2-propanol (i.e.,tert-butanol), 1-pentanol, 2-pentanol, 3-pentanol,2,2-dimethyl-1-propanol, 1-hexanol, cyclopentanol, 3-methyl-1-butanol,3-methyl-2-butanol, 2-methyl-1-butanol, 2,2-dimethyl-1-propanol,3-hexanol, 2-hexanol, 4-methyl-2-pentanol, 2-methyl-1-pentanol,2-ethylbutanol, 2,4-dimethyl-3-pentanol, 3-heptanol, 4-heptanol,2-heptanol, 1-heptanol, 2-ethyl-1-hexanol, 2,6-dimethyl-4-heptanol,2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol, andthe like, as well as combinations of any two or more thereof. In oneembodiment, the alcohol co-dispersing liquid is methanol, ethanol, orisopropanol.

Exemplary alcohol ether co-dispersing liquids contemplated for use inthe new composition include, but are not limited to, 2-butoxyethanol,1-methoxy-2-propanol, 2-methoxyethanol, 2-ethoxyethanol,1-methoxy-2-butanol, ethylene glycol monoisopropyl ether,1-ethoxy-2-propanol, 3-methoxy-1-butanol, ethylene glycol monoisobutylether, ethylene glycol mono-n-butyl ether, 3-methoxy-3-methylbutanol,ethylene glycol mono-tert-butyl ether, and the like, as well ascombinations of any two or more thereof. In one embodiment, the alcoholether co-dispersing liquid is 1-methoxy-2-propanol, 2-methoxyethanol, or2-butoxyethanol.

Exemplary ketone co-dispersing liquids contemplated for use in the newcomposition include, but are not limited to, acetone, methylethylketone, methyl iso-butyl ketone, cyclohexanone, isopropyl methyl ketone,2-pentanone, 3-pentanone, 3-hexanone, diisopropyl ketone, 2-hexanone,cyclopentanone, 4-heptanone, iso-amyl methyl ketone, 3-heptanone,2-heptanone, 4-methoxy-4-methyl-2-pentanone, 5-methyl-3-heptanone,2-methylcyclohexanone, diisobutyl ketone, 5-methyl-2-octanone,3-methylcyclohexanone, 2-cyclohexen-1-one, 4-methylcyclohexanone,cycloheptanone, 4-tert-butylcyclohexanone, isophorone, benzyl acetone,and the like, as well as combinations of any two or more thereof.

Exemplary nitrile co-dispersing liquids contemplated for use in the newcomposition include, but are not limited to, acetonitrile,acrylonitrile, trichloroacetonitrile, propionitrile, pivalonitrile,isobutyronitrile, n-butyronitrile, methoxyacetonitrile,2-methylbutyronitrile, isovaleronitrile, n-valeronitrile,n-capronitrile, 3-methoxypropionitrile, 3-ethoxypropionitrile,3,3′-oxydipropionitrile, n-heptanenitrile, glycolonitrile, benzonitrile,ethylene cyanohydrin, succinonitrile, acetone cyanohydrin,3-n-butoxypropionitrile, and the like, as well as combinations of anytwo or more thereof.

Exemplary sulfoxide co-dispersing liquids contemplated for use in thenew composition include, but are not limited to, dimethyl sulfoxide(DMSO), di-n-butyl sulfoxide, tetramethylene sulfoxide, methyl phenylsulfoxide, and the like, as well as combinations of any two or morethereof.

Exemplary amide co-dispersing liquids contemplated for use in the newcomposition include, but are not limited to, dimethyl formamide (DMF),dimethyl acetamide, acylamide, 2-acetamidoethanol,N,N-dimethyl-m-toluamide, trifluoroacetamide, N,N-dimethylacetamide,N,N-diethyldodecanamide, ε-caprolactam, N,N-diethylacetamide,N-tert-butylformamide, formamide, pivalamide, N-butyramide,N,N-dimethylacetoacetamide, N-methyl formamide, N,N-diethylformamide,N-formylethylamine, acetamide, N,N-diisopropylformamide,1-formylpiperidine, N-methylformanilide, and the like, as well ascombinations of any two or more thereof.

Exemplary amine co-dispersing liquids contemplated for use in the newcomposition include, but are not limited to, mono-, di-, and tri-alkylamines, cyclic amines (such as, e.g., pyrrolidine), aromatic amines(such as, e.g., pyridine) and the like, as well as combinations of anytwo or more thereof. In one embodiment, the amine co-dispersing liquidis pyridine.

Exemplary carboxylic acid co-dispersing liquids contemplated for use inthe new composition include, but are not limited to, C₁ up to about C₆straight or branched chain carboxylic acids, as well as combinations ofany two or more thereof. In one embodiment, the carboxylic acidco-dispersing liquid is formic acid.

In one embodiment, the co-dispersing liquid comprises a liquid selectedfrom, n-propanol, isopropanol, methanol, butanol, 1-methoxy-2-propanol,dimethylacetamide, n-methyl pryrozole, 1,4-dioxane, tetrahydrofuran,tetrahydropyran, 4 methyl-1,3-dioxane, 4-phenyl-1,3-dioxane,1,3-dioxolane, 2-methyl-1,3-dioxolane, 1,3-dioxane,2,5-dimethoxytetrahydrofuran, 2,5-dimethoxy-2,5-dihydrofuran,1-methylpyrrolindine, 1-methyl-2-pyrrolidinone, dimethylsulfoxide, andcombinations of any two or more thereof.

In one embodiment, after completion of any of the methods describedabove and completion of the polymerization reaction, the as-synthesizedaqueous dispersion is contacted with at least one ion exchange resinunder conditions suitable to remove decomposed species, side reactionproducts, unreacted monomers, and ionic impurities, and to adjust pH.The as-synthesized aqueous dispersion can be contacted with at least oneion exchange resin before or after the addition of a co-dispersingliquid. In one embodiment, the as-synthesized aqueous dispersion iscontacted with a first ion exchange resin and a second ion exchangeresin.

In another embodiment, the first ion exchange resin is an acidic, cationexchange resin, such as a sulfonic acid cation exchange resin set forthabove, and the second ion exchange resin is a basic, anion exchangeresin, such as a tertiary amine or a quaternary exchange resin.

Ion exchange is a reversible chemical reaction wherein an ion in a fluidmedium (such as an aqueous dispersion) is exchanged for a similarlycharged ion attached to an immobile solid particle that is insoluble inthe fluid medium. The term “ion exchange resin” is used herein to referto all such substances. The resin is rendered insoluble due to thecrosslinked nature of the polymeric support to which the ion exchanginggroups are attached. Ion exchange resins are classified as acidic,cation exchangers, which have positively charged mobile ions availablefor exchange, and basic, anion exchangers, whose exchangeable ions arenegatively charged.

Both acidic, cation exchange resins and basic, anion exchange resins arecontemplated for use in the new process. In one embodiment, the acidic,cation exchange resin is an organic acid, cation exchange resin, such asa sulfonic acid cation exchange resin. Sulfonic acid cation exchangeresins contemplated for use in the new composition include, for example,sulfonated styrene-divinylbenzene copolymers, sulfonated crosslinkedstyrene polymers, phenol-formaldehyde-sulfonic acid resins,benzene-formaldehyde-sulfonic acid resins, and mixtures thereof. Inanother embodiment, the acidic, cation exchange resin is an organicacid, cation exchange resin, such as carboxylic acid, acrylic orphosphoric acid cation exchange resin. In addition, mixtures ofdifferent cation exchange resins can be used. In many cases, the basicion exchange resin can be used to adjust the pH to the desired level. Insome cases, the pH can be further adjusted with an aqueous basicsolution such as a solution of sodium hydroxide, ammonium hydroxide, orthe like.

In another embodiment, the basic, anionic exchange resin is a tertiaryamine anion exchange resin. Tertiary amine anion exchange resinscontemplated for use in the new compositions include, for example,tertiary-aminated styrene-divinylbenzene copolymers, tertiary-aminatedcrosslinked styrene polymers, tertiary-aminated phenol-formaldehyderesins, tertiary-aminated benzene-formaldehyde resins, and mixturesthereof. In a further embodiment, the basic, anionic exchange resin is aquaternary amine anion exchange resin, or mixtures of these and otherexchange resins.

The first and second ion exchange resins may contact the as-synthesizedaqueous dispersion either simultaneously, or consecutively. For example,in one embodiment both resins are added simultaneously to anas-synthesized aqueous dispersion of an electrically conducting polymer,and allowed to remain in contact with the dispersion for at least about1 hour, e.g., about 2 hours to about 20 hours. The ion exchange resinscan then be removed from the dispersion by filtration. The size of thefilter is chosen so that the relatively large ion exchange resinparticles will be removed while the smaller dispersion particles willpass through. Without wishing to be bound by theory, it is believed thatthe ion exchange resins quench polymerization and effectively removeionic and non-ionic impurities and most of unreacted monomer from theas-synthesized aqueous dispersion. Moreover, the basic, anion exchangeand/or acidic, cation exchange resins renders the acidic sites morebasic, resulting in increased pH of the dispersion. In general, at least1 gram of ion exchange is used per about 1 gram of colloid-formingpolymeric acid. In other embodiments, the use of the ion exchange resinis used in a ratio of up to about 5 grams of ion exchange resin topolythiophene/polymeric acid colloid and depends on the pH that is to beachieved. In one embodiment, about one gram of Lewatit® MP62 WS, aweakly basic anion exchange resin from Bayer GmbH, and about one gram ofLewatit® MonoPlus S100, a strongly acidic, sodium cation exchange resinfrom Bayer, GmbH, are used per gram of the composition of polythiophenehaving Formula I(a) or Formula I(b) and at least one colloid-formingpolymeric acid.

In one embodiment, the aqueous dispersion resulting from polymerizationof thiophene having Formula II(a) or Formula II(b) with fluorinatedpolymeric sulfonic acid colloids is to charge a reaction vessel firstwith an aqueous dispersion of the fluorinated polymer, and then, inorder, add the oxidizing agent, catalyst and thiophene monomer; or, inorder, the thiophene monomer, the oxidizing agent and catalyst to theaqueous dispersion of the colloid-forming polymeric acid. The mixture isstirred and the reaction is then allowed to proceed at a controlledtemperature. When polymerization is completed, the reaction is quenchedwith a strong acid cation resin and a base anion exchange resin, stirredand filtered. Alternatively, the thiophene having Formula II(a) orFormula II(b) can be added to water and stirred to homogenize themixture prior to addition of Nafion® dispersion, followed with oxidizingagent and catalyst. The oxidizing agent:monomer ratio is generally inthe range of 0.5 to 2.0. The fluorinated polymer:thiophene monomer ratiois generally in the range of 1 to 4. The overall solid content isgenerally in the range of 1.5% to 6%; and in one embodiment 2% to 4.5%.The reaction temperature is generally in the range of 5° C. to 50° C.;and in one embodiment 20° C. to 35° C. The reaction time is generally inthe range of 1 to 30 hours.

Aqueous dispersions of polythiophenes of Formula I(a) or Formula I(b)and polymer acid colloids can have a wide range of pH and can beadjusted to typically be between about 1 to about 8, and generally havea pH of about 3-4. It is frequently desirable to have a higher pH, asthe acidity can be corrosive. It has been found that the pH can beadjusted using known techniques, for example, ion exchange or bytitration with an aqueous basic solution.

In another embodiment, more conductive dispersions are formed by theaddition of highly conductive additives to the aqueous dispersions ofpolythiophene having Formula I(a) or Formula I(b) and thecolloid-forming polymeric acid. In one embodiment, new compositions withrelatively high pH can be formed, and further comprise the conductiveadditives, especially metal additives, which are not attacked by theacid in the dispersion. Moreover, because the polymeric acids arecolloidal in nature, having the surfaces predominately containing acidgroups, electrically conducting polythiophene is formed on the colloidalsurfaces.

In one embodiment, the new composition further comprises at least oneconductive additive at a weight percentage of an amount to reach thepercolation threshold. Examples of suitable conductive additivesinclude, but are not limited to conductive polymers, metal particles andnanoparticles, metal nanowires, carbon nanotubes, carbon nanopoarticles,graphite fibers or particles, carbon particles, and combinationsthereof. A dispersing agent may be included to faciltate dispersing ofthe conductive additives.

In one embodiment, the new compositions are deposited to formelectrically conductive or semiconductive layers which are used alone,or in combination with other electroactive materials, as electrodes,electroactive elements, photoactive elements, or bioactive elements. Asused herein, the terms “electroactive element”, “photoactive element”and “bioactive element” refer to elements which exhibit the namedactivity in response to a stimulus, such as an electromagnetic field, anelectrical potential, solar energy radiation, and a biostimulationfield.

In one embodiment, the new compositions are deposited to form bufferlayers in an electronic device. The term “buffer layer” as used herein,is intended to mean an electrically conductive or semiconductive layerwhich can be used between an anode and an active organic material. Abuffer layer is believed to accomplish one or more function in anorganic electronic device, including, but not limited to planarizationof the underlying layer, hole transport, hole injection, scavenging ofimpurities, such as oxygen and metal ions, among other aspects tofacilitate or to improve the performance of an organic electronicdevice.

In one embodiment, there are provided buffer layers deposited from anaqueous dispersion containing polythiophene having Formula I(a) orFormula I(b) and fluorinated polymeric acid colloids. In anotherembodiment, the fluorinated polymeric acid colloids are fluorinatedpolymeric sulfonic acid colloids. In still another embodiment, thebuffer layer is deposited from an aqueous dispersion containingpolythiophene having Formula I(a) or Formula I(b) andperfluoroethylenesulfonic acid colloids.

In another embodiment, there are provided buffer layers deposited fromaqueous dispersions comprising at least one polythiophene having FormulaI(a) or Formula I(b), at least one colloid-forming polymeric acid, andat least one co-dispersing liquid. In one embodiment, the co-dispersingliquid is selected from n-propanol, isopropanol, t-butanol, methanoldimethylacetamide, dimethylformamide, N-methylpyrrolidone, ethyleneglycol, and mixtures thereof.

In one embodiment, the dried layers of polythiophenes having FormulaI(a) or Formula I(b) and polymeric acid colloids, such as fluorinatedpolymeric sulfonic acid colloids, are not redispersible in water. In oneembodiment, the organic device comprising at least one layer comprisingthe new composition is made of multiple thin layers. In one embodiment,the layer can be further overcoated with a layer of differentwater-soluble or water-dispersible material without substantial damageto the layer's functionality or performance in an organic electronicdevice.

In another embodiment, there are provided buffer layers deposited fromaqueous dispersions comprising at least one polythiophene having FormulaI(a) or Formula I(b) and at least one colloid-forming polymeric acidsblended with other water soluble or dispersible materials. Depending onthe final application of the material, examples of types of additionalwater soluble or dispersible materials which can be added include, butare not limited to polymers, dyes, coating aids, carbon nanotubes, metalnanowires and nanoparticles, organic and inorganic conductive inks andpastes, charge transport materials, piezoelectric, pyroelectric, orferroelectric oxide nano-particles or polymers, photoconductive oxidenanoparticles or polymers, dispersing agents, crosslinking agents, andcombinations thereof. The materials can be simple molecules or polymers.Examples of suitable other water soluble or dispersible polymersinclude, but are not limited to, polyacrylamide, polyvinylalcohol,poly(2-vinylpridine), poly(vinylacetate), poly(vinylmethylether),poly(vinylpyrrolidone), poly(vinylbutyral), poly(styrenesulfonic acid,and conductive polymers such as polythiophenes, polyanilines,polyamines, polypyrroles, polyacetylenes, colloid-forming polymericacids, and combinations thereof.

In another embodiment, there are provided electronic devices comprisingat least one electrically conductive or semiconductive layer made fromthe new composition. Organic electronic devices that may benefit fromhaving one or more layers comprising the composition of at least onepolythiophene having Formula I(a) or Formula I(b), and at least onecolloid-forming polymeric acids and include, but are not limited to, (1)devices that convert electrical energy into radiation (e.g., alight-emitting diode, light emitting diode display, or diode laser), (2)devices that detect signals through electronics processes (e.g.,photodetectors (e.g., photoconductive cells, photoresistors,photoswitches, phototransistors, phototubes), IR detectors), (3) devicesthat convert radiation into electrical energy, (e.g., a photovoltaicdevice or solar cell), and (4) devices that include one or moreelectronic components that include one or more organic semi-conductorlayers (e.g., a transistor or diode). Other uses for the newcompositions include coating materials for memory storage devices,antistatic films, biosensors, electrochromic devices, solid electrolytecapacitors, energy storage devices such as a rechargeable battery, andelectromagnetic shielding applications.

In one embodiment, the organic electronic device comprises anelectroactive layer positioned between two electrical contact layers,wherein at least one of the layers of the device includes the new bufferlayer. One embodiment is illustrated in one type of OLED device, asshown in FIG. 1, which is a device that has anode layer 110, a bufferlayer 120, an electroluminescent layer 130, and a cathode layer 150.Adjacent to the cathode layer 150 is an optionalelectron-injection/transport layer 140. Between the buffer layer 120 andthe cathode layer 150 (or optional electron injection/transport layer140) is the electroluminescent layer 130.

The device may include a support or substrate (not shown) that can beadjacent to the anode layer 110 or the cathode layer 150. Mostfrequently, the support is adjacent the anode layer 110. The support canbe flexible or rigid, organic or inorganic. Generally, glass or flexibleorganic films are used as a support. The anode layer 110 is an electrodethat is more efficient for injecting holes compared to the cathode layer150. The anode can include materials containing a metal, mixed metal,alloy, metal oxide or mixed oxide. Suitable materials include the mixedoxides of the Group 2 elements (i.e., Be, Mg, Ca, Sr, Ba, Ra), the Group11 elements, the elements in Groups 4, 5, and 6, and the Group 8-10transition elements. If the anode layer 110 is to be light transmitting,mixed oxides of Groups 12, 13 and 14 elements, such as indium-tin-oxide,may be used. As used herein, the phrase “mixed oxide” refers to oxideshaving two or more different cations selected from the Group 2 elementsor the Groups 12, 13, or 14 elements. Some non-limiting, specificexamples of materials for anode layer 110 include, but are not limitedto, indium-tin-oxide (“ITO”), aluminum-tin-oxide, gold, silver, copper,and nickel. The anode may also comprise an organic material such aspolyaniline, polythiophene, or polypyrrole. The IUPAC number system isused throughout, where the groups from the Periodic Table are numberedfrom left to right as 1-18 (CRC Handbook of Chemistry and Physics,81^(st) Edition, 2000).

The anode layer 110 may be formed by a chemical or physical vapordeposition process or spin-coating process. Chemical vapor depositionmay be performed as a plasma-enhanced chemical vapor deposition(“PECVD”) or metal organic chemical vapor deposition (“MOCVD”). Physicalvapor deposition can include all forms of sputtering, including ion beamsputtering, as well as e-beam evaporation and resistance evaporation.Specific forms of physical vapor deposition include rf magnetronsputtering and inductively-coupled plasma physical vapor deposition(“IMP-PVD”). These deposition techniques are well known within thesemiconductor fabrication arts.

The anode layer 110 may be patterned during a lithographic operation.The pattern may vary as desired. The layers can be formed in a patternby, for example, positioning a patterned mask or resist on the firstflexible composite barrier structure prior to applying the firstelectrical contact layer material. Alternatively, the layers can beapplied as an overall layer (also called blanket deposit) andsubsequently patterned using, for example, a patterned resist layer andwet chemical or dry etching techniques. Other processes for patterningthat are well known in the art can also be used. When the electronicdevices are located within an array, the anode layer 110 typically isformed into substantially parallel strips having lengths that extend insubstantially the same direction.

The buffer layer 120 can be deposited onto substrates using anytechniques well-known to those skilled in the art.

The electroluminescent (EL) layer 130 may typically be any organic ELmaterial, including, but not limited to, fluorescent dyes, fluorescentand phosphorescent metal complexes, conjugated polymers, and mixturesthereof. Examples of fluorescent dyes include, but are not limited to,pyrene, perylene, rubrene, derivatives thereof, and mixtures thereof.Examples of metal complexes include, but are not limited to, metalchelated oxinoid compounds, such as tris(8-hydroxyquinolato)aluminum(Alq3); cyclometalated iridium and platinum electroluminescentcompounds, such as complexes of Iridium with phenylpyridine,phenylquinoline, or phenylpyrimidine ligands as disclosed in Petrov etal., Published PCT Application WO 02/02714, and organometallic complexesdescribed in, for example, published applications US 2001/0019782, EP1191612, WO02/15645, and EP 1191614; and mixtures thereof.Electroluminescent emissive layers comprising a charge carrying hostmaterial and a metal complex have been described by Thompson et al., inU.S. Pat. No. 6,303,238, and by Burrows and Thompson in published PCTapplications WO 00/70655 and WO 01/41512. Examples of conjugatedpolymers include, but are not limited to poly(phenylenevinylenes),polyfluorenes, poly(spirobifluorenes), polythiophenes,poly(p-phenylenes), copolymers thereof, and mixtures thereof.

The particular material chosen may depend on the specific application,potentials used during operation, or other factors. The EL layer 130containing the electroluminescent organic material can be applied usingany number of techniques including vapor deposition, solution processingtechniques or thermal transfer. In another embodiment, an EL polymerprecursor can be applied and then converted to the polymer, typically byheat or other source of external energy (e.g., visible light or UVradiation).

Optional layer 140 can function both to facilitate electroninjection/transport, and can also serve as a confinement layer toprevent quenching reactions at layer interfaces. More specifically,layer 140 may promote electron mobility and reduce the likelihood of aquenching reaction if layers 130 and 150 would otherwise be in directcontact. Examples of materials for optional layer 140 include, but arenot limited to, metal-chelated oxinoid compounds (e.g., Alq₃ or thelike); phenanthroline-based compounds (e.g.,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (“DDPA”),4,7-diphenyl-1,10-phenanthroline (“DPA”), or the like); azole compounds(e.g., 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (“PBD” orthe like), 3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole(“TAZ” or the like); other similar compounds; or any one or morecombinations thereof. Alternatively, optional layer 140 may be inorganicand comprise BaO, LiF, Li₂O, or the like.

The cathode layer 150 is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode layer 150can be any metal or nonmetal having a lower work function than the firstelectrical contact layer (in this case, the anode layer 110). As usedherein, the term “lower work function” is intended to mean a materialhaving a work function no greater than about 4.4 eV. As used herein,“higher work function” is intended to mean a material having a workfunction of at least approximately 4.4 eV.

Materials for the cathode layer can be selected from alkali metals ofGroup 1 (e.g., Li, Na, K, Rb, Cs,), the Group 2 metals (e.g., Mg, Ca,Ba, or the like), the Group 12 metals, the lanthanides (e.g., Ce, Sm,Eu, or the like), and the actinides (e.g., Th, U, or the like).Materials such as aluminum, indium, yttrium, and combinations thereof,may also be used. Specific non-limiting examples of materials for thecathode layer 150 include, but are not limited to, barium, lithium,cerium, cesium, europium, rubidium, yttrium, magnesium, samarium, andalloys and combinations thereof.

The cathode layer 150 is usually formed by a chemical or physical vapordeposition process. In general, the cathode layer will be patterned, asdiscussed above in reference to the anode layer 110. If the device lieswithin an array, the cathode layer 150 may be patterned intosubstantially parallel strips, where the lengths of the cathode layerstrips extend in substantially the same direction and substantiallyperpendicular to the lengths of the anode layer strips. Electronicelements called pixels are formed at the cross points (where an anodelayer strip intersects a cathode layer strip when the array is seen froma plan or top view).

In other embodiments, additional layer(s) may be present within organicelectronic devices. For example, a layer (not shown) between the bufferlayer 120 and the EL layer 130 may facilitate positive charge transport,band-gap matching of the layers, function as a protective layer, or thelike. Similarly, additional layers (not shown) between the EL layer 130and the cathode layer 150 may facilitate negative charge transport,band-gap matching between the layers, function as a protective layer, orthe like. Layers that are known in the art can be used. In addition, anyof the above-described layers can be made of two or more layers.Alternatively, some or all of inorganic anode layer 110, the bufferlayer 120, the EL layer 130, and cathode layer 150, may be surfacetreated to increase charge carrier transport efficiency. The choice ofmaterials for each of the component layers may be determined bybalancing the goals of providing a device with high device efficiencywith the cost of manufacturing, manufacturing complexities, orpotentially other factors.

The different layers may have any suitable thickness. In one embodiment,inorganic anode layer 110 is usually no greater than approximately 500nm, for example, approximately 10-200 nm; buffer layer 120, is usuallyno greater than approximately 250 nm, for example, approximately 50-200nm; EL layer 130, is usually no greater than approximately 100 nm, forexample, approximately 50-80 nm; optional layer 140 is usually nogreater than approximately 100 nm, for example, approximately 20-80 nm;and cathode layer 150 is usually no greater than approximately 100 nm,for example, approximately 1-50 nm. If the anode layer 110 or thecathode layer 150 needs to transmit at least some light, the thicknessof such layer may not exceed approximately 100 nm.

In organic light emitting diodes (OLEDs), electrons and holes, injectedfrom the cathode 150 and anode 110 layers, respectively, into the ELlayer 130, form negative and positively charged polar ions in thepolymer. These polar ions migrate under the influence of the appliedelectric field, forming a polar ion exciton with an oppositely chargedspecies and subsequently undergoing radiative recombination. Asufficient potential difference between the anode and cathode, usuallyless than approximately 12 volts, and in many instances no greater thanapproximately 5 volts, may be applied to the device. The actualpotential difference may depend on the use of the device in a largerelectronic component. In many embodiments, the anode layer 110 is biasedto a positive voltage and the cathode layer 150 is at substantiallyground potential or zero volts during the operation of the electronicdevice. A battery or other power source(s) may be electrically connectedto the electronic device as part of a circuit but is not illustrated inFIG. 1.

In one embodiment, OLEDs comprising at least one buffer layer depositedfrom aqueous dispersions comprising at least one polythiophenes havingFormula I(a) or Formula I(b) and at least one colloid-forming polymericacids have been found to have improved lifetimes. The buffer layer maybe deposited from an aqueous dispersion of polythiophene having FormulaI(a) or Formula I(b) and fluorinated polymeric sulfonic acid colloids;in one embodiment the buffer layer is depositing using any solutionprocessing technique and is an aqueous dispersion in which the pH hasbeen adjusted to above about 3.5.

In one embodiment a pH neutral composition is used in at least one layerof an electronic device. In one OLED embodiment, the pH is adjusted soas to reduce etching of the ITO layer during device fabrication andhence much lower concentration of In and Sn ions diffusing into thepolymer layers of the OLED. Since In and Sn ions are suspected tocontribute to reduced operating lifetime this is a significant benefit.The lower acidity also reduces corrosion of the metal components of thedisplay (e.g. electrical contact pads) during fabrication and over thelong-term storage. PEDT/PSSA residues will interact with residualmoisture to release acid into the displays with resulting slowcorrosion.

Equipment used to dispense the acidic PEDT/PSSA needs to be speciallydesigned to handle the strong acidity of PEDT/PSSA. For example, achrome-plated slot-die coating-head used to coat the PEDT/PSSA onto ITOsubstrates was found to be corroding due to the acidity of thePEDT/PSSA. This rendered the head unusable since the coated film becamecontaminated with particles of chrome. Also, certain ink-jet print headsare of interest for the fabrication of OLED displays. They are used fordispensing both the buffer layer and the light-emitting polymer layer inprecise locations on the display. These print-heads contain nickel meshfilters as an internal trap for particles in the ink. These nickelfilters are decomposed by the acidic PEDT/PSSA and rendered unusable.Neither of these corrosion problems will occur with the aqueouspolythiophene dispersions of the new compositions in which the acidityhas been lowered.

Furthermore, certain light-emitting polymers are found to be sensitiveto acidic conditions, and their light-emitting capability is degraded ifthey are in contact with an acidic buffer layer. It is advantageous touse the aqueous dispersions of the new compositions to form the bufferlayer because the ability to adjust pH to a lower acidity or neutrality.

In one embodiment the fabrication of full-color or area-color displaysusing two or more different light-emitting materials becomes complicatedif each light-emitting material requires a different cathode material tooptimize its performance. Display devices are made up of a multiplicityof pixels which emit light. In multicolor devices there are at least twodifferent types of pixels (sometimes referred to as sub-pixels) emittinglight of different colors. The sub-pixels are constructed with differentlight-emitting materials. It is very desirable to have a single cathodematerial that gives good device performance with all of the lightemitters. This minimizes the complexity of the device fabrication. Whenthe buffer layer is made from the aqueous polythiophene dispersions ofthe new composition, It may be possible to use a common cathode inmulticolor devices while maintaining good device performance for each ofthe colors. The cathode can be made from any of the materials discussedabove; and may be barium, overcoated with a more inert metal such asaluminum.

The layer in an organic electronic device comprising the new compositionmay further comprise a layer of conductive polymer applied from aqueoussolution or solvent. The conductive polymer can facilitate chargetransfer and also improve coatability. Examples of suitable conductivepolymers include, but are not limited to, polyanilines, polythiophenes,polydioxythiophene/polystyrenesulfonic acid,polyaniline/polymeric-acid-colloids such as those disclosed inco-pending application Ser. No. 10/669,577,polythiophene/polymeric-acid-colloids such as those disclosed inco-pending application Ser. No. 10/669,494, polypyrroles,polyacetylenes, and combinations thereof. The composition comprisingsuch a layer may further comprise conductive polymers, and may alsocomprise dyes, carbon nanotubes, carbon nanoparticles, metal nanowires,metal nanoparticles, carbon fibers and particles, graphite fibers andparticles, coating aids, organic and inorganic conductive inks andpastes, charge transport materials, semiconductive or insulatinginorganic oxide particles, piezoelectric, pyroelectric, or ferroelectricoxide nano-particles or polymers, photoconductive oxide nanoparticles orpolymers, dispersing agents, crosslinking agents and combinationsthereof. These materials can be added to the new composition eitherbefore or after polymerization of the monomer and/or before or aftertreatment with at least one ion exchange resin.

In one embodiment, there are provided thin film field effect transistorscomprising electrodes comprising polythiophenes comprising at least oneof the Formula I(a) or Formula I(b) and at least one colloid-formingpolymeric sulfonic acid. For use as electrodes in thin film field effecttransistors, the conducting polymers and the liquids for dispersing ordissolving the conducting polymers must be compatible with thesemiconducting polymers and the solvents for the semiconducting polymersto avoid re-dissolution of either conducting polymers or semiconductingpolymers. Thin film field effect transistor electrodes fabricated fromconducting polymers should have a conductivity greater than 10 S/cm.However, electrically conducting polymers made with water solublepolymeric acids only provide conductivity in the range of ˜10⁻³ S/cm orlower. Thus, in one embodiment, the electrodes comprise polythiophenecomprising at least one of the Formula I(a) or Formula I(b) andfluorinated colloid-forming polymeric sulfonic acids in combination withelectrical conductivity enhancers such as metal nanowires, metalnanoparticles, carbon nanotubes, or the like. The new compositions maybe used in thin film field effect transistors as gate electrodes, drainelectrodes, or source electrodes.

Another illustration of a use for the new composition, is the thin filmfield effect transistors, is shown in FIG. 2. In this illustration, adielectric polymer or dielectric oxide thin film 210 has a gateelectrode 220 on one side and drain and source electrodes, 230 and 240,respectively, on the other side. Between the drain and source electrode,an organic semiconducting film 250 is deposited. New aqueous dispersionscontaining nanowires or carbon nanotubes are ideal for the applicationsof gate, drain and source electrodes because of their compatibility withorganic based dielectric polymers and semiconducting polymers insolution thin film deposition. Since new compositions as a colloidaldispersion, less weight percentage of the conductive fillers is required(relative to compositions containing water soluble polymeric sulfonicacids) to reach percolation threshold for a desired or high electricalconductivity.

In another embodiment, there are provided field effect resistancedevices comprising one layer comprising at least one polythiophenehaving Formula I(a) or Formula I(b) and at least one colloid-formingpolymeric sulfonic acids. The field effect resistance devices undergo areversible change of resistance in the conducting polymer films whensubjected to a pulse of gate voltage, as illustrated in pages 339-343,No. 2, 2002, Current Applied Physics.

In another embodiment, there are provided electrochromic displayscomprising at least one layer comprising at least one polythiophenehaving Formula I(a) or Formula I(b) and at least one colloid-formingpolymeric sulfonic acids. Electrochromic displays utilize change ofcolor when thin film of the material is subjected to electricalpotential. In one embodiment electrically conductivepolythiophene/polymeric acid colloids of the new composition aresuperior materials for this application because of the high pH of thedispersion, and the low moisture uptake and water non-dispersibility ofdried solid films made from the dispersions.

In yet another embodiment, there are provided memory storage devicescomprising silicon chips top-coated with a composition comprising atleast one polythiophene having Formula I(a) or Formula I(b) and at leastone colloid-forming polymeric sulfonic acids. For example, awrite-once-read-many-times (WORM) memory is known in the arts (Nature,Page 166 to 169, vol 426, 2003). When information is recorded, highervoltages at certain points in the circuit grids of silicon chipsdestroys the polythiophene at those points to create “zero” bit data.The polythiophene at the untouched points remains electricallyconductive and becomes “1” bit data.

In another embodiment, the new aqueous dispersions comprising at leastone polythiophene having Formula I(a) or Formula I(b) and at least onecolloid forming polymeric acid are used to form coatings for biosensor,electrochromic, andi-static, anti-corrosion, solid electrolytecapacitors, or electromagnetic shielding applications.

In another embodiment, the new compositions can be used for antistaticcoatings for plastic and cathode ray tubes, electrode materials forsolid electrolyte capacitors, metal anti-corrosion coatings,through-hole plating of printed circuit boards, photodiodes,bio-sensors, photodetectors, rechargeable batteries, photovoltaicdevices, and photodiodes. In addition, examples of other applicationsfor the new compositions can be found in, for example, AdvancedMaterials, page 490 to 491, vol. 12, No. 7, 2000.

In another embodiment, there are provided methods for producing, aqueousdispersions of polythiophene having Formula I(a) or Formula I(b) and atleast one colloid-forming polymeric acid comprising polymerizingthiophene monomers having Formula II(a) or Formula II(b) in the presenceof polymeric sulfonic acid colloids. The polymerization is carried outin the presence of water. The resulting reaction mixture can be treatedwith ion exchange resins to remove reaction byproducts and to adjust thepH of the dispersion. The new compositions and its uses will now bedescribed in greater detail by reference to the following non-limitingexamples.

EXAMPLES Example 1

This Example illustrates polymerization of (sulfonicacid-propylene-ether-methylene-3,4-dioxyethylene)thiophene in thepresence of Nafion®. A 25% (w/w) aqueous colloidal dispersion ofperfluroethylenesulfonic acid with an EW of 990 is made using aprocedure similar to the procedure in U.S. Pat. No. 6,150,426, Example1, Part 2, except that the temperature is approximately 270° C. Thedispersion is diluted with water to form a 12.5% (w/w) dispersion forthe polymerization.

63.87 g (8.06 mmoles of Nafion® monomer units) Nafion® aqueous colloidaldispersion, and 234.47 g deionized water will be massed into a 500 mLjacketed three-necked round bottom flask. The mixture will be stirredfor 45 minutes before the addition of ferric sulfate and sodiumpersulfate. A stock solution of ferric sulfate will be made first bydissolving 0.0141 g ferric sulfate hydrate (97%, Aldrich cat. #30,771-8)with deionized water to a total weight of 3.6363 g. 0.96 g (0.0072mmoles) of the ferric sulfate solution and 0.85 g (3.57 mmoles) sodiumpersulfate (Fluka, cat. # 71899) will be then placed into the reactionflask while the mixture will be stirred. The mixture will then bestirred for 3 minutes prior to addition of 0.8618 g (2.928 mmoles) of(sulfonic acid-propylene-ether-methylene-3,4-dioxyethylene)thiophenemonomer. The monomer will be added to the reaction mixture whilestirring. The polymerization will be allowed to proceed with stirring atabout 20° C. controlled by circulation fluid. The polymerization will beterminated in 16 hours by adding 8.91 g Lewatit® S100, a trade name fromBayer, Pittsburgh, Pa., for sodium sulfonate of crosslinked polystyrene,and 7.70 g Lewatit® MP62 WS, a trade from Bayer, Pittsburgh, Pa., forfree base/chloride of tertiary/quaternary amine of crosslinkedpolystyrene. The two resins will be washed first before use withdeionized water separately until there will be no color in the water.The resin treatment will proceed for 5 hrs. The resulting slurry willthen be suction-filtered through a Whatman #54 filter paper.

Example 2

This Example illustrates polymerization of(propyl-ether-ethylene-3,4-dioxyethylene)thiophene in the presence ofNafion®. The Nafion® will be the same as in Example 1.

63.87 g (8.06 mmoles of Nafion® monomer units) Nafion® aqueous colloidaldispersion, and 234.47 g deionized water will be massed into a 500 mLjacketed three-necked round bottom flask. The mixture will be stirredfor 45 minutes before the addition of ferric sulfate and sodiumpersulfate. A stock solution of ferric sulfate will be made first bydissolving 0.0141 g ferric sulfate hydrate (97%, Aldrich cat. #30,771-8)with deionized water to a total weight of 3.6363 g. 0.96 g (0.0072mmoles) of the ferric sulfate solution and 0.85 g (3.57 mmoles) sodiumpersulfate (Fluka, cat. # 71899) will be then placed into the reactionflask while the mixture will be stirred. The mixture will then bestirred for 3 minutes prior to addition of 0.6685 g (2.928 mmoles) of(propyl-ether-ethylene-3,4-dioxyethylene)thiophene monomer. The monomerwill be added to the reaction mixture while stirring. The polymerizationwill be allowed to proceed with stirring at about 20° C. controlled bycirculation fluid. The polymerization will be terminated in 16 hours byadding 8.91 g Lewatit® S100, a trade name from Bayer, Pittsburgh, Pa.,for sodium sulfonate of crosslinked polystyrene, and 7.70 g Lewatit®MP62 WS, a trade from Bayer, Pittsburgh, Pa., for free base/chloride oftertiary/quaternary amine of crosslinked polystyrene. The two resinswill be washed first before use with deionized water separately untilthere will be no color in the water. The resin treatment will proceedfor 5 hrs. The resulting slurry will then be suction-filtered through aWhatman #54 filter paper.

Example 3

This example illustrates slow injection of both ethylenedioxythiophene(“EDT”) monomer and oxidizing agent solution into the reaction mixturecontaining iron(III) sulfate catalyst, water, Nafion® and HCl co-acid.The Nafion® used is the same as in Example 1.

In a 2000 mL reaction kettle are put 715 g of 12% solid content aqueousNafion® dispersion (82 mmol SO₃H groups), 1470 g water, 0.5 g (0.98mmol) iron(III)sulfate (Fe₂(SO₄)₃), and 1406 μL of 37% HCl (18.1 mmol).The reaction mixture is stirred for 15 minutes at 200 RPM using anoverhead stirrer fitted with a double stage propeller type blade beforeaddition of 7.78 g (32.8 mmol) sodium persulfate (Na₂S₂O₈) in 60 mL ofwater, and 3.17 mL ethylenedioxythiophene (EDT). The addition is startedfrom separate syringes using addition rate of 0.9 mL/h for Na₂S₂O₈/waterand 50 μL/h for EDT while continuously stirring at 200 RPM. EDT additionis accomplished by placing the monomer in a syringe connected to aTeflon® tube that leads directly into the reaction mixture. The end ofthe Teflon® tube connecting the Na₂S₂O₈/water solution is placed abovethe reaction mixture such that the injection involves individual dropsfalling from the end of the tube such that the injection is gradual. Thereaction is stopped 2 h after the addition of monomer has finished byadding 170 g of each Lewatit MP62WS and Lewatit Monoplus S100ion-exchange resins, and 225 g of n-propanol to the reaction mixture andstirring it further for 4 h at 150 RPM. The ion-exchange resin isfinally filtered from the solution using Whatman No. 54 filter paper. pHof the dispersion is 4 and dried films derived from the dispersion haveconductivity of 1.4×10⁻⁴ S/cm at room temperature.

Analysis by an Atomic Force Microscope (AFM) of films resulting fromspin-coating dispersion onto ITO substrates revealed that allparticulates in the film were smaller than 60 nm in height (multiple50×50 μm scans). In comparison, films spun from dispersions made usingprocedures where all of the monomer is rapidly added in one portion,have large count of particles up to 200 nm tall and up to 500 nm wide.

Organic light emitting diodes (OLEDs) were fabricated to the followingspecifications: 6×6″ substrates containing patterned indium-tin-oxideanodes, were cleaned in an oxygen plasma (300 W) for 10 minutes. Thenapproximately 75 nm thick film of the buffer was spun followed by bakingat 130° C. on a hotplate for 10 minutes. After cooling down to roomtemperature, the plate was spun with approximately 75 nm thick film ofLumination Green 1303 electroluminescent polymer from Dow Chemicals(from 1% w/v solution in p-Xylene) in air. Following the baking of theelectroluminescent film at 130° C. in a vacuum oven for 40 minutes, acathode consisting of 4 nm of Ba and 500 nm of Al was thermallyevaporated at pressure less then 10⁻⁶ Torr. Encapsulation of the deviceswas achieved by bonding a glass slide on the back of the devices using aUV-curable epoxy resin.

The resulting devices (16 devices total with 300 mm² active area) hadefficiency of 19.2±0.5 cd/A @ 1000 cd/m2 at room temperature and arectification ratio of 1000 at ±5V. Five devices were stressed with aconstant current of 16.2 mA (approximately 900 cd/m²) at 80° C. After1000 h the light output had decreased on average by 32% or ˜600 cd/m².

Example 4

This example illustrates slow injection of both EDT monomer andoxidizing agent solution into the reaction mixture containing iron(III)sulfate catalyst, water, Nafion® and H₂SO₄ co-acid. The Nafion® is thesame as in Example 1.

In a 200 mL reaction kettle are put 715 g of 12% solid content aqueousNafion®D (82 mmol SO₃H groups) dispersion, 1530 g water, 0.5 g (0.98mmol) iron(III)sulfate (Fe₂(SO₄)₃), and 1011 μL of concentrated H₂SO₄(18.1 mmol). The reaction mixture is stirred for 15 min at 276 RPM usingan overhead stirrer fitted with a double stage propeller type blade,before addition of 8.84 g (37.1 mmol) sodium persulfate (Na₂S₂O₈) in 60mL of water, and 3.17 mL ethylenedioxythiophene (EDT) is started fromseparate syringes using addition rate of 4.2 mL/h for Na₂S₂O₈/water and224 μL/h for EDT while continuously stirring at 276 RPM. The addition ofEDT is accomplished by placing the monomer in a syringe connected to aTeflon® tube that leads directly into the reaction mixture. The end ofthe Teflon® tube connecting the Na₂S₂O₈/water solution was placed abovethe reaction mixture such that the injection involved individual dropsfalling from the end of the tube. The reaction is stopped 7 hours afterthe addition of monomer has finished by adding 170 g of each LewatitMP62WS and Lewatit Monoplus S100 ion-exchange resins, and 225 g ofn-propanol to the reaction mixture and stirring it further for 7 hoursat 130 RPM. The ion-exchange resin is finally filtered from thedispersion using Whatman No. 54 filter paper. The pH of the dispersionis ˜4 and dried films derived from the dispersion have conductivity of2.6×10⁻⁵ S/cm at room temperature.

Organic light emitting diodes (OLEDs) are fabricated to the followingspecifications: 6×6″ substrates containing patterned indium-tin-oxideanodes partially covered with 600 nm thick photo-resist for device areadefinition, were cleaned in an UV-Ozone oven for 10 min. Thenapproximately 75 nm thick film of the buffer layer from thePEDOT/Nafion® made above is spun followed by baking at 130° C. on ahotplate for 10 min. After cooling down to room temperature, the plateis spun with approximately 75 nm thick film of Lumination Green 1303electroluminescent polymer from Dow Chemicals (from 1% w/v solution inp-xylene) in air. Following the baking of the electroluminescent film at130° C. in a vacuum oven for 40 min, a cathode consisting of 4 nm of Baand 500 nm of Al is thermally evaporated at pressure less than 10⁻⁶Torr. Encapsulation of the devices is achieved by bonding a glass slideon the back of the devices using a UV-curable epoxy resin.

The resulting devices (25 mm² active area) have an efficiency of 20±1cd/A @ 1000 cd/m² and a rectification ratio of 13000 @±5V. Six devicesare stressed with a constant current of 50 mA/cm² (approximately 8,000cd/m²) at 25° C. In 220 h the luminance drops to half the initial value.

Example 5

This example illustrates the effect of the addition of ethylene glycolon the conductivity of as-synthesized PEDOT/Nafion®:

An aqueous PEDT/Nafion®, used for this example was prepared as follows:

0.309 ml (2.902 mmoles) of Baytron-M (a trade name for3,4-ethyylenedioxythiophene) from H. C. Starck GmbH (Leverkusen,Germany) was predissolved in 229.12 g deionized water at 20° C. for onehour in a 500 ml jacketed three-necked round bottom flask equipped witha stirrer at a speed of 175 RPM. 69.52 g (8.0 mmoles of Nafion® monomerunits) DE1021 (E. I. du Pont de Nemours and Company (Wilmington, Del.,USA; EW: 999 g/mole acid) Nafion® was then massed into the mixture. Assoon as the Nafion® was added, 0.84 g (3.538 mmoles) sodium persulfatepre-dissoved in 10 g deionized water was added to the reaction vessel.0.95 g (7.1 mmoles) of a stock solution of ferric sulfate was thenadded. The stock solution of ferric sulfate was made first by dissolving0.0141 g ferric sulfate hydrate (97%, Aldrich cat. #30,771-8) withdeionized water to a total weight of 3.6363 g. The polymerization wasallowed to proceed with stirring at about 20° C. controlled bycirculation fluid. The polymerization liquid started to turn blue in 13minutes. The reaction was terminated in 14 hours by adding 11.03 gLewatit® S100, a trade name from Bayer, Pittsburgh, Pa., for sodiumsulfonate of crosslinked polystyrene, and 11.03 g Lewatit® MP62 WS, atrade from Bayer, Pittsburgh, Pa., for free base/chloride oftertiary/quaternary amine of crosslinked polystyrene. The two resinswere washed first before use with deionized water separately until therewas no color in the water. The resin treatment proceeded for about 6hrs. The resulting slurry was then suction-filtered through a Whatman#54 filter paper. It went through the filter paper very fast. Yield was268 g. Solid % was about 2.8% (w/w) based on added polymerizationingredients. pH of the aqueous PEDT/Nafion® was determined to be 4.64with a 315 pH/Ion meter from Corning Company (Corning, N.Y., USA).

A couple drops of the dispersion made above were spread on a microscopeslide, which was left dried in ambient conditions before placed in avacuum oven set at 90° C. for 30 minutes. The oven was constantly fedwith a small amount of flowing nitrogen. Once baked, the dried filmshaving thickness of ˜2 μm were painted with approximately 0.4 cmparallel vertical lines with a separation of about 0.15 cm between eachtwo parallel lines. The thickness was measured using a Surface Profilier(model# Alpha-Step 500, from Tencor Instrument, San Jose, Calif., USA).Resistance was then measured at ambient temperature by applying voltagebetween 1 and −1 volt using a Keithley 2420 Source Meter. Averageconductivity of five samples was 1.1×10⁻⁵ S/cm. It should be pointed outthat the films used for resistance measurement do not re-disperse inwater. 9.5021 g of the aqueous dispersion, which contains 0.266 g solidand 9.2361 g water, was mixed with 0.499 g ethylene glycol (AcrossOrganics, Cat# 295530010) and stirred for 3 hours. It formed a smoothdispersion, which contains 2.7% (w/w) PEDOT/Nafion®, and 5.0% (w/w)ethylene glycol. Couple drops of the dispersion made above were spreadon a microscope slide. The films left dried on a hot plate set at ˜50°C. in ambient conditions before placed in a vacuum oven set at 90° C.for 50 minutes. The oven was constantly fed continuously with a smallamount of flowing nitrogen. Once baked, the dried films having thicknessof ˜6 μm were painted with approximately 0.4 cm parallel vertical lineswith a separation of about 0.15 cm between each two parallel lines.Resistance was then measured at ambient temperature by applying voltagebetween 1 and −1 volt. Average conductivity of four samples was 2.9×10⁻⁴S/cm. The conductivity is about 30 times the conductivity of the filmsmade from as-synthesized PEDOT/Nafion®.

7.9981 g of the aqueous dispersion, which contains 0.2239 g solid and7.7742 g water, was mixed with 2.0154 g ethylene glycol (AcrossOrganics, Cat# 295530010) and stirred for 3 hours. It formed a smoothdispersion which contains 2.2% (w/w) PEDOT/Nafion® and 20.1% (w/w)ethylene glycol. Films preparation and resistance are as described for5% ethylene glycol. Once baked, the dried films having thickness of ˜3μm were painted with approximately 0.4 cm parallel vertical lines with aseparation of about 0.152 cm between each two parallel lines. Resistancewas then measured at ambient temperature by applying voltage between 1and −1 volt. Average conductivity of four samples was 4.6×10⁻⁴ S/cm. Theconductivity is about 46 times the conductivity of the films made fromas-synthesized PEDOT/Nafion®.

Example 6

This example illustrates one ink-jetting application of PEDOT/Nafion®with added ethylene glycol:

The preparation of one of the four large batches (1,700 g) of aqueousPEDOT/Nafion® dispersion, which was combined for microfluidization forparticle size reduction, is described below. The Nafion® used for thepolymerization is the same as in Example 1 with an EW of 1050.

366.1 g (46.13 mmoles of Nafion® monomer units) Nafion® aqueouscolloidal dispersion, and 1693.7 g deionized water was massed into a2000 ml jacketed three-necked round bottom flask. The mixture wasstirred for 2 hrs at a stirring speed of 425 RPM before the addition offerric sulfate and sodium persulfate. A stock solution of ferric sulfatewas made first by dissolving 0.1017 g ferric sulfate hydrate (97%,Aldrich cat. #30,771-8) with deionized water to a total weight of19.4005 g. 4.07 g (0.0413 mmoles) of the ferric sulfate solution and4.88 g (40.99 mmoles) sodium persulfate (Fluka, cat. # 71899) were thenplaced into the reaction flask while the mixture was being stirred. Themixture was then stirred for 4 minutes prior to addition of 1.790 ml(16.796 mmoles) of Baytron-M (a trade name for3,4-ethyylenedioxythiophene H. C. Starck, LeverKusen, Germany) was addedto the reaction mixture while stirring. The polymerization was allowedto proceed with stirring at about 20° C. controlled by circulationfluid. The polymerization liquid started to turn blue in 13 minutes. Thereaction was terminated in 7 hours by adding 44.17 g Lewatit® S100, atrade name from Bayer, Pittsburgh, Pa., for sodium sulfonate ofcrosslinked polystyrene, and 48.80 g Lewatit® MP62 WS, a trade fromBayer, Pittsburgh, Pa., for free base/chloride of tertiary/quaternaryamine of crosslinked polystyrene. The two resins were washed firstbefore use with deionized water separately until there was no color inthe water. The resin treatment proceeded for 5 hrs. The resulting slurrywas then suction-filtered through a Whatman #54 filter paper. It wentthrough the filter paper very fast. Solid % was about 3.0% (w/w). Fourbatches made in the same manner as described above were combined andmicrofluidized with a Microfluidizer Processor M-110Y (Microfluidics,Massachusetts, USA) using a pressure of 5,000-7,000 psi for five passes.The diameter of first pressure chamber and second pressure chamber is200 μm (H30Z model).

Viscosity and surface tension are two most critical physical propertiesfor ink-jet printing. They effect drop formation, jet stability,substrate wetting, spreading and leveling as well as drying phenomena.Viscosity of the 3% PEDOT/Nafion® is about 1.9 cp at 60 rpm and theviscosity of 1% is about 0.9 cp at 60 rpm. The obtained printing surfaceis not very smooth. The viscosity is too low and the surface tension istoo high for effective ink-jet printing. Therefore, ethylene glycol wasadded as described below, which should improve conductivity asdemonstrated in Example 5, increase viscosity, lower the surface tensionof PEDOT/Nafion®.

8.0 ml (density ˜1.008 g/ml) of the microfluidized aqueous dispersionwas added with 14 ml deionized water and 4.0 ml ethylene glycol (density˜1.113 g/ml; Acros Organics, Cat# 295530010). The composition contains0.91% (w/w) PEDOT/Nafion®, 16.9% ethylene glycol. The ink was filteredthrough HV filter after mixed well. Viscosity of the ink was measured tobe 2.45 cps at 60 rpm.

Microfab (single-nuzzle system) was used for ink-jet printing. A 30 umtip was back-flushed with DI water and blow-dried with N2. Theink-jetting head was set-up, and a stable and clean drop was obtainedusing 15 volts with 45 us dwell time. A full-drizzle 1 um undercut plate(5206) was treated with UV-Ozone for 15 minutes, then treated with CF4plasma for 3 minutes. The plate was placed at the printing stage at roomtemperature. Display 1, 2, 3, 4 were printed. For Display 1, Row 1 toRow 5 were printed with 7 drops per pixel, R6 to R 10 were printed with8 drops per pixel, R16 to R 20 were printed with 9 drops per pixel, andR 21 to R 25 were printed with 10 drops per pixel. For Display 4, R11 toR15 were printed with 11 drops per pixel, R21 to R25 were printed 12drops per pixel, R26 to R 30 were printed 13 drops per pixel, and R 31to R 35 were printed with 14 drops per pixel. Then the plate was heatedto 40° C., Display 5, 6, and 7 were printed with 8 drops, 10 drops, 12drops per pixel, respectively. The plate after printed was baked at 130Cunder vacuum for 30 minutes.

0.91% PEOT/Nafion® with 16.9% ethylene glycol added gave higherviscosity (2.45 cps at 60 rpm) than that of 1% PEDOT/Nafion® aqueous ink(0.9 cps at 60 rpm). 0.91% PEDOT/Nafion®/EG ink gave better printabilitythan 1% aqueous Nafion® aqueous system. Stable and clean drops withoutsatellites were obtained easily with low voltage (15 v). Nuzzlestability was also improved by adding 16.9% ethylene glycol. Smoothsurface was obtained with PEDOT/Nafion®/EG ink.

Example 7

This Example illustrates the preparation of an aqueous dispersion ofPEDT/Nafion® and the effect of the addition of methanol on electricalconductivity and particle size.

73.46 g (8.81 mmoles) Nafion® aqueous colloidal dispersion and 224.8 gdeionized water was massed into a 500 ml jacketed three-necked roundbottom flask. Nafion® DE1020 (a commercial perfluoroethylenesulfonicacid from E. I. du Pont de Nemours and Company, Wilmington, Del.) was an11.4% (w/w) aqueous colloidal dispersion having an EW of 951 g/acidequivalent. The mixture was allowed to stir for 20° C. for 30 minutes.0.469 ml (4.40 mmoles) of Baytron-M (a trade name for3,4-ethyylenedioxythiophene from H.C. Starck, MA, USA) was added to theNafion®/water mixture and was allowed to stir for 15 more minutes beforeaddition of ferric sulfate and sodium persulfate. 1.10 g (4.62 mmoles)sodium persulfate (Fluka, cat. # 71899) was first dissolved in 5 gdeionized water in a glass vial and then transferred to the rationmixture while the mixture was being stirred. A stock solution of ferricsulfate was made first by dissolving 0.0141 g ferric sulfate hydrate(97%, Aldrich cat. #30,771-8) with deionized water to a total weight of3.6363 g. 1.44 g (0.0108 mmoles) of the ferric sulfate stock solutionadded to the reaction flask immediately after the addition of the ferricsulfate solution. The polymerization was allowed to proceed withstirring at about 20° C. controlled by circulation fluid. Thepolymerization liquid started to turn blue in 13 minutes. The reactionwas terminated in 12 hours by adding 9.61 g Lewatit® S100, a trade namefrom Bayer, Pittsburgh, Pa., for sodium sulfonate of crosslinkedpolystyrene, and 9.61 g Lewatit® MP62 WS, a trade from Bayer,Pittsburgh, Pa., for free base/chloride of tertiary/quaternary amine ofcrosslinked polystyrene. The two resins were washed first before usewith deionized water separately until there was no color in the water.The resin treatment proceeded for 10 hrs. The resulting slurry was thensuction-filtered through a Buchner Funnel containing two pieces ofWhatman #4 filter paper. It went through the filter paper very fast.Yield was 290 g. Solid % was about 3.0% (w/w) based on addedpolymerization ingredients. pH of the aqueous PEDT/Nafion® wasdetermined to be 4.95 with a 315 pH/Ion meter from Corning Company(Corning, N.Y., USA). Electrical conductivity of the as-made dispersionwas determined to be 2.6×10⁻⁶ S/cm using a two-probe resistancemeasurement technique. A small portion of the dispersion was added with10% (w/w) methanol. Conductivity was determined to be 3.8×10⁻⁶ S/cm,which shows that conductivity remains similar with addition of themethanol. However, the effect on particle size count, measured with anAccusizer (Model 780A, Particle Sizing Systems, Santa Barbara, Calif.),is pronounced as illustrated in Table I, which shows number of particlesper one mL dispersion, which have particle size greater than 0.75 μm,1.51 μm, and 2.46 μm, respectively. The data clearly shows that methanolnot only stabilizes the PEDT/Nafion® particles, but also reduces numberof large particles substantially.

TABLE 1 Methanol (10%) >0.75 μm >1.51 μm >2.46 μm Without 355,488 57,44817,983 (As-made) Without (14 400,122 69,948 21,849 days) With (3 hr)262,795 38,816 10,423 With (27 hr) 245,573 34,586 9,477 With (14 days)18,864 8,252 4,233

Example 8

This Example illustrates the preparation of an aqueous dispersion ofPEDT/Nafion® and the effect of the addition of n-propanol on particlesize. The Nafion® used was the same as in Example 1.

In a 500 mL reaction kettle are put 85.9 g of 12% solid content aqueousNafion® dispersion (9.8 mmol SO₃H groups), 313 g water, 1.86 g (7.8mmol) sodium perisulfate (Na₂S₂O₈), and 0.084 g (0.125 mmol)iron(III)sulfate (Fe₂(SO₄)₃. The reaction mixture is stirred for 15 minat 180 RPM using a propeller type blade before addition of 0.695 mL (6.5mmol) ethylenedioxythiophene (EDT) is started using addition rate of 20μL/h while continuously stirring at 180 RPM. The addition of EDT isaccomplished by placing the monomer in a syringe connected to a Teflon®tube that leads directly into the reaction mixture. The reaction isstopped 36 h after the addition of monomer has finished by adding 25 gof each Lewatit MP62WS and Lewatit Monoplus S100 ion-exchange resins tothe reaction mixture and stirring for 3 h at 180 RPM. The ion-exchangeresin is finally filtered from the solution using Whatman No. 54 filterpaper. Portion of the dispersion is diluted by 10% w/w with n-propanol.After 60 h, particle count, measured an Accusizer (Model 780A, ParticleSizing Systems, Santa Barbara, Calif.), of PEDT/Nafion® particles of thedispersion prior to and after addition of n-propanol is shown in TableII and FIG. 1. The data clearly shows that n-propanol, a low boilingliquid, has reduced the number of large PEDT/Nafion® particlessubstantially.

TABLE 2 n-Propanol (10%) >0.75 μm >1.51 μm >2.46 μm Without 2,430,000593,000 100,000 With 211,000 33,000 8000

Example 9

This Example illustrates preparation of an aqueous dispersion ofPEDT/Nafion®. The Nafion® used was the same as in Example 1.

63.89 g (8.07 mmoles of Nafion® monomer units) Nafion® (990 EW) aqueouscolloidal dispersion (12.5%, w/w) and 234.79 g deionized water wasmassed into a 500 ml jacketed three-necked round bottom flask. Themixture was stirred for 45 minutes before addition of ferric sulfate andsodium persulfate. A stock solution of ferric sulfate was made first bydissolving 0.0135 g ferric sulfate hydrate (97%, Aldrich cat. #30,771-8)with deionized water to a total weight of 3.5095 g. 0.97 g (0.0072mmoles) of the ferric sulfate solution and 0.85 g (3.57 mmoles) sodiumpersulfate (Fluka, cat. # 71899) were then placed into the reactionflask while the mixture was being stirred. The mixture was then stirredfor 3 minutes prior to addition of 0.312 ml (2.928 mmoles) of Baytron-M(a trade name for 3,4-ethylene dioxythiophene from Bayer, Pittsburgh,Pa.) to the reaction mixture while stirring. The polymerization wasallowed to proceed with stirring at about 20° C. controlled bycirculation fluid. The polymerization liquid turned medium dark blue inhalf an hour. The reaction was terminated after 19.6 hours by adding8.97 g Lewatit® S100 (a trade name from Bayer, Pittsburgh, Pa., forsodium sulfonate of crosslinked polystyrene) and 7.70 g Lewatit® MP62 WS(a trade from Bayer, Pittsburgh, Pa., for free base/chloride oftertiary/quaternary amine of crosslinked polystyrene). The two resinswere washed first before use with deionized water separately until therewas no color in the water. The resin treatment was allowed to proceedfor 5 hrs. The resulting slurry was then suction-filtered through aWhatman #54 filter paper. It went through the filter paper readily. Theyield was 273.7 g. The solid % was about 3.1% (w/w) based on addedpolymerization ingredients.

Example 10

This example illustrates the effect of added co-dispersing liquid on thesurface tension of the PEDT/Nafion® dispersion.

The surface tension of the aqueous PEDT/Nafion® from Example 9, withoutany co-dispersing liquid, was measured with a FTA T10 Tensiometer Model1000 IUD (KSV Instruments, Finland) and determined to be 73 milliN/meterat 19.5° C.

To determine effect of the co-dispersing liquid on the surface tension,25.436 ml of the PEDT/Nafion® from Example 1 was mixed with 1.4781 mln-propanol (n-PA) and 2.051 ml 1-methoxy-2-propanol (1M2P), whichconstitutes 87.8 V.% PEDT/Nafion®, 5.1 V.% n-PA, and 7.1 V.% 1M2P. Themixture of dispersion and co-dispersing liquid was very smooth having noindication of precipitation. The surface tension of the dispersion withco-dispersing liquid was determined to be 42.24 mN/m. The lower surfacetension of the new dispersion indicates its increased wetability andease of coating.

Example 11

This example illustrates effect of co-dispersing liquids on lightemitting diode performance.

The aqueous PEDT/Nafion® dispersion prepared in Example 9 and theco-dispersing liquid mix described in Example 10 were tested for lightemission properties. The glass/ITO substrates (30 mm×30 mm) having ITOthickness of 100 to 150 nm and 15 mm×20 mm ITO area for light emissionwere cleaned and subsequently treated with oxygen plasma. The aqueousPEDT/Nafion® dispersions with and without the co-dispersing liquids werespin-coated onto the ITO/glass substrates. The thickness was 75 nm forboth with and without the dispersing liquids. The PEDT/Nafion® coatedITO/glass substrates were dried in vacuum at 90° C. for 30 minutes. ThePEDT/Nafion® layer was then top-coated with HS670 blue emitting polymerfrom Covion Organic Semiconductors GmbH (Frankfurt, Germany). Thethickness of the EL layer was approximately 75 nm. The film thicknesswas measured with a TENCOR 500 Surface Profiler. The HS670 top-coatedstructure was then baked at 100° C. for 10 minutes in vacuum. Ba and Allayers were vapor deposited on top of the EL layers under a vacuum of1×10⁻⁶ torr. The final thickness of the Ba layer was 30 Å; the thicknessof the Al layer was 4000 Å. The devices made from PEDT/Nafion® with theco-dispersing liquids have a higher efficiency (6.0 Cd/A) than thedevices made without the co-dispersing liquids in the aqueousPEDT/Nafion® (4.5 Cd/A) although they have similar voltage (˜4.2 volt).Device luminance and voltage as a function of time are shown in FIG. 11.The devices made with the new dispersions, which contain a co-dispersingliquid, have a longer half-life at 80° C. (100 hrs) than the devicesmade from dispersions of aqueous PEDT/Nafion® alone (50 hrs.).

While the invention has been described in detail with reference tocertain preferred embodiments thereof, it will be understood thatmodifications and variations are within the spirit and scope of thatwhich is described and claimed.

1. An electrically conductive composition comprising an aqueousdispersion capable of forming a film of at least one polythiophene andat least one colloid-forming fluorinated polymeric sulfonic acid,wherein said polythiophene has Formula I(a):

wherein: R″ is the same or different at each occurrence and is selectedfrom the group consisting of hydrogen, alkyl, heteroalkyl, alkenyl,heteroalkenyl, alcohol, amidosulfonate, benzyl, carboxylate, ether,ether carboxylate, ether sulfonate, sulfonate, and urethane, with theproviso that at least one R″ is not hydrogen, m is 2 or 3, and n is atleast about
 4. 2. A composition according to claim 1, wherein at leastabout 50% of the total number of halogen and hydrogen atoms in saidfluorinated polymeric acid are fluorine atoms.
 3. A compositionaccording to claim 2, also comprising sulfonic acid salt groups.
 4. Acomposition according to claim 1, wherein said fluorinated polymericsulfonic acid is perfluorinated.
 5. A composition according to claim 4,also comprising sulfonic acid salt groups.
 6. A composition according toclaim 1, further comprising at least one additional material selectedfrom polymers, conductive polymers, colloid-forming polymeric acids,dyes, carbon nanotubes, metal nanowires, metal nanoparticles, carbonnanoparticles, carbon fibers, carbon particles, graphite fibers,graphite particles, coating aids, organic conductive inks, organicconductive pastes, inorganic conductive inks, inorganic conductivepastes, charge transport materials, semiconductive inorganic oxidenano-particles, insulating inorganic oxide nano-particles, piezoelectricnano-particles, pyroelectric nano-particles, ferroelectric oxidenano-particles, piezoelectric polymers, pyroelectric polymers,ferroelectric oxide polymers, photoconductive oxide nanoparticles,photoconductive oxide polymers, dispersing agents, crosslinking agents,and combinations thereof.
 7. A composition according to claim 1, furthercomprising at least one co-dispersing liquid.
 8. A composition accordingto claim 7, wherein the co-dispersing liquid is selected from the groupconsisting of ethers, cyclic ethers, alcohols, alcohol ethers, ketones,nitriles, sulfides, sulfoxides, amides, amines, carboxylic acids, andcombinations thereof.
 9. A composition according to claim 7, wherein theco-dispersing liquid is at least one liquid selected from the groupconsisting of n-propanol, isopropanol, methanol, butanol,1-methoxy-2-propanol, dimethylacetamide, n-methyl pyrrozole,1,4-dioxane, tetrahydrofuran, tetrahydropyran, 4 methyl-1,3-dioxane,4-phenyl-1,3-dioxane, 1,3-dioxolane, 2-methyl-1,3-dioxolane,1,3-dioxane, 2,5-dimethoxytetrahydrofuran,2,5-dimethoxy-2,5-dihydrofuran, 1-methylpyrrolindine,1-methyl-2-pyrrolidinone, dimethylsulfoxide, and combinations thereof.10. A composition according to claim 1, also comprising sulfonic acidsalt groups.
 11. A composition according to claim 1, wherein thesulfonic acid has a functional group represented by the formula,—SO₃X wherein X is selected from the group consisting of H, Li, Na, K,and N(R₁)(R₂)(R₃)(R₄) where R₁, R₂, R₃, and R₄ are the same or differentand selected from the group consisting of H, —CH₃, or —CH₂CH₃, and ametal, represented by the formula M^(n+) where the number of functionalgroups is equal to the valence value of n.